1. Field of the Invention
The present invention relates to brackets for mounting of electrical equipment, such as electrical outlet and junction boxes, primarily to vertical metal or wooden studs in the space between two walls, during building construction and/or repair. In particular, the present invention relates to extension brackets for use with such mounting brackets to augment the effective length of the brace or stabilizer portion of the mounting bracket.
2. Background of the Prior Art
As used herein, the term "outlet box" is intended to refer to an outlet box, a junction box or both. When outlet boxes are supported from a metal or wooden stud, it has been found desirable to stabilize the cantilevered box and bracket. U.S. Pat. No. 3,767,151 illustrates one means of stabilizing an outlet box by attaching a bracket directly to the box. In U.S. Pat. No. 4,057,164, an adjustable screw is used for stabilizing an outlet box. U.S. Pat. No. 4,399,922 illustrates a unitary mounting bracket in which a portion of the bracket is formed as a brace to stabilize both the bracket and the outlet box and in which break-away strips are employed to vary the length of the brace. Other outlet box mounting brackets suited to utilizing the extension stabilizer plate of the invention are shown in U.S. Pat. Nos. 4,572,391, 4,603,789, 4,688,693, 4,753,361 and 4,757,908. Useful background to the present invention may also be found in U.S. Pat. Nos. 4,533,060 and 4,569,458.
In an outlet box mounting bracket of the type suited to the present invention, one portion of the mounting bracket is typically comprised of a front plate adapted for mounting the outlet box, and another portion comprises a stabilizer plate formed at a right angle to the front plate and which functions as a brace extending between the interior walls. The space between two drywalls in a construction is typically 21/2", 31/2", 4", 5" or 6", although other dimensions may be used. Differently shaped front plates may be employed for such an outlet mounting bracket, depending upon the application for which the mounting bracket is to be used. While each variation of front plate might be manufactured for each commonly used wall space size, it would obviously be desirable to minimize the number of different types of mounting brackets required on the job. The use of an adjustably mounted extension plate attached to the stabilizer plate permits manufacture of a stabilizer plate geared to a single shorter size of wall space, with primarily reliance placed upon the extension plate to accommodate wider spaces between walls. U.S. Pat. No. 4,732,356 discloses a bendable mounted extension plate which is capable of being mounted at an adjustable variety of lengths to the bracket stabilizer plate, according to the choice of which set of screw holes on the extension plate one chooses to mate with a corresponding set of screw holes on the bracket stabilizer plate.
However, in practice, screw mounted extension stabilizer plates have been found to be somewhat troublesome to stabilize in position for attachment while the screws are being inserted, particularly with powered screwdriver tools. Also, screws add an incremental expense to the cost of the brackets and to the cost of installation. In the situation of the electrical contractor for a large building in which a large number of outlet boxes must be mounted, this added cost can be considerable. A further desirable goal in any construction setting, particularly where adverse weather may sometimes be part of the working environment, is to minimize the need for workers to remove their gloves to adequately achieve installation of the extension stabilizer plates as is sometimes presently required.
With the foregoing as background, the object of the invention is to provide an improved outlet box extension stabilizer plate which permits attachment without the need for screws, is adaptable to a variety of wall spacings and is readily installed by the worker when wearing gloves. Other objects will become apparent as the description proceeds.